A wideband microstrip array antenna with the 2nd harmonic suppression characteristics

A wideband microstrip array antenna with the 2^nd harmonic suppression characteristics is presented in this paper. The array antenna is comprised of a 16-element microstrip dipole array and 16 low-pass microstrip shunt-open stub filters. The 2^nd harmonic suppression function is achieved using a 9 step low-pass microstrip shunt-open stub filter. The low-profile and wide-band microstrip dipole antenna is effectively employed in forming this type of antenna array. It providing 42% bandwidth with VSWR lower than 1.8. And the operating frequency range covers 8 ~ 12GHz. Experimental results show that the proposed array antenna has good 2^nd harmonic suppression characteristics with gain suppression better than 20dB. Consequently, a wideband microstrip array antenna with the 2^nd harmonic suppression function is successfully verified.